<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>CSS样式表</title>
    <!-- 1.内嵌样式 -->
    <style>
        h1 {
            /* CSS注释 */
            color: yellow;
            background-color: red;
        }
    </style>
    <!-- 2.外链样式
    link 点击tab
    -->
    <link rel="stylesheet" href="css/demo11.css">
</head>
<body>
    <h1>内嵌样式</h1>
    <h2>外部样式</h2>
    <!-- 3.行内样式 -->
    <h3 style="color: green;background-color: lightblue;">行内样式</h3>
</body>
</html>